Monitoring media exposure using wireless communications

ABSTRACT

Disclosed examples involve collecting a cookie at a client device based on media accessed via a web page at the client device, and selecting a portable device identifier at the client device. The portable device identifier corresponds to a closest one of a plurality of portable devices in wireless communication with the client device. The portable device identifier is associated with a particular person. In response to instructions embedded in the media, a hypertext transfer protocol (HTTP) request is sent to a server. The HTTP request includes the cookie, the portable device identifier, and information identifying exposure to the media.

RELATED APPLICATIONS

This patent arises from a continuation of U.S. patent application Ser.No. 14/303,032, filed Jun. 12, 2014, which is a continuation ofInternational Patent Application No. PCT/US12/70162, filed Dec. 17,2012, which claims the benefit of U.S. patent application Ser. No.13/327,943, filed Dec. 16, 2011, now U.S. Pat. No. 8,538,333, all ofwhich are hereby incorporated herein by reference in their entireties.

TECHNICAL FIELD

The present disclosure is directed to processor-based audienceanalytics. More specifically, the disclosure describes systems andmethods for combining characteristics of Bluetooth signals with researchdata to identify and characterize devices and their accompanying usersassociated with media consumption.

BACKGROUND INFORMATION

Bluetooth is a proprietary open wireless technology standard forexchanging data over short distances from fixed and mobile devices,creating personal area networks (PANs) with high levels of security.Bluetooth uses a radio technology called frequency-hopping spreadspectrum, which divides the data being sent and transmits portions of iton up to 79 bands (1 MHz each, preferably centered from 2402 to 2480MHz) in the range 2,400-2,483.5 MHz (allowing for guard bands). Thisrange is in the globally unlicensed Industrial, Scientific and Medical(ISM) 2.4 GHz short-range radio frequency band. Gaussian frequency-shiftkeying (GFSK) modulation may be used, however, more advanced techniques,such as π/4-DQPSK and 8DPSK modulation may also be used betweencompatible devices. Devices functioning with GFSK are said to beoperating in “basic rate” (BR) mode where an instantaneous data rate of1 Mbit/s is possible. “Enhanced Data Rate” (EDR) is used to describeπ/4-DPSK and 8DPSK schemes, each giving 2 and 3 Mbit/s respectively. Thecombination of these (BR and EDR) modes in Bluetooth radio technology isclassified as a “BR/EDR radio”.

Bluetooth is a packet-based protocol with a master-slave structure. Onemaster may communicate with up to 7 slaves in a piconet, where alldevices preferably share the master's clock. Packet exchange is based onthe basic clock, defined by the master, which may tick at 312.5 μsintervals. In the simple example of single-slot packets, the mastertransmits in even slots and receives in odd slots; the slave,conversely, receives in even slots and transmits in odd slots. Packetsmay be 1, 3 or 5 slots long but in all cases the master transmit willbegin in even slots and the slave transmit in odd slots.

Bluetooth provides a secure way to connect and exchange informationbetween devices such as faxes, mobile phones, telephones, laptops,personal computers, printers, Global Positioning System (GPS) receivers,digital cameras, and video game consoles. At any given time, data can betransferred between the master and one other device. The master maychoose which slave device to address and may switch rapidly from onedevice to another in a round-robin fashion. In the area of computerprocessors, Bluetooth is commonly used to operationally link devices tothe computer processor. In other cases, Bluetooth signals are used to“unlock” a computer processor when an enabled device is within a certainproximity.

One area where improvements are needed is in the area of media exposuretracking and web analytics. To date, Bluetooth has been relativelyunderutilized in this area. What is needed are methods, systems andapparatuses for utilizing Bluetooth signal characteristics inconjunction with media exposure data to produce research data thataccurately identifies and characterizes devices, and their accompanyingusers.

SUMMARY

Accordingly, apparatuses, systems and methods are disclosed forcomputer-implemented techniques for establishing media data exposure fora computer processing device, where media data is received in thecomputer processing device, which pairs itself with a plurality ofportable computing devices (e.g., smart phone, PPM™, tablet, laptop,etc.) using a Bluetooth connection when media data is received. A signalstrength characteristic of the Bluetooth connection is established inthe computer processing device for each of the paired plurality ofportable computing devices. Each signal strength characteristic is thenassociated with the received media data to determine which signalstrength characteristic is the strongest when the media data wasreceived in the computer processing device. The exposure data comprisesat least one of a cookie, a logfile and a page tag, while the media datacomprises at least one of audio, video, audio/video, text, an image, aweb page and streaming media. The signal strength characteristic of theBlue tooth connection comprises at least one of a Received SignalStrength Indicator (RSSI) value, a Transmit Power Level (TPL) value anda Link Quality (LQ) value.

Under another embodiment, apparatuses, systems and methods are disclosedfor computer-implemented techniques for establishing media data exposurefor a computer processing device. Media exposure data is stored relatingto media data received in the computer processing device, as well aspairing data of the computer processing device with a plurality ofportable computing devices using a Bluetooth connection when media datais received. A signal strength characteristic of the Bluetoothconnection is received for each of the paired plurality of portablecomputing devices and each signal strength characteristic is associatedwith the received media data to determine which signal strengthcharacteristic is the strongest when the media data was received in thecomputer processing device. The strongest signal strength characteristicthen associated with the media exposure data. The exposure datacomprises at least one of a cookie, a logfile and a page tag, while themedia data comprises at least one of audio, video, audio/video, text, animage, a web page and streaming media. The signal strengthcharacteristic of the Bluetooth connection comprises at least one of aReceived Signal Strength Indicator (RSSI) value, a Transmit Power Level(TPL) value and a Link Quality (LQ) value.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and notlimitation in the figures of the accompanying drawings, in which likereferences indicate similar elements and in which:

FIG. 1 illustrates an exemplary system under one embodiment, where mediadata is provided from a network to a processing device in the vicinityof a plurality of portable devices;

FIG. 2 illustrates an exemplary Bluetooth protocol stack utilized forcommunication in the embodiment of FIG. 1;

FIG. 3 illustrates an exemplary service discovery process;

FIG. 4 illustrates an exemplary authentication mechanism for connecteddevices;

FIG. 5 is an exemplary flowchart for monitoring an RSSI Bluetooth signalcharacteristic; and

FIG. 6 illustrates an exemplary media exposure table for a plurality ofmedia data that was exposed to one or more of a plurality of devices.

DETAILED DESCRIPTION

FIG. 1 illustrates an exemplary system 100 that comprises a computerprocessing device 101 and a plurality of portable computing devices(102-104) that are in the vicinity of processing device 101. In thisexample, processing device 101 is illustrated as a personal computer,while portable computing devices 102-104 are illustrated asBluetooth-enabled cell phones. It is understood by those skilled in theart that other similar devices may be used as well. For example,processing device 101 may also be a laptop, a computer tablet, a set-topbox, a media player, a network-enabled television or DVD player, and thelike. Portable computing devices 102-104 may also be laptops, PDAs,tablet computers, Personal People Meters™ (PPMs), wireless telephone,etc.

Under a preferred embodiment, processing device 101 connects to contentsource 125 via network 110 to obtain media data. The terms “media data”and “media” as used herein mean data which is widely accessible, whetherover-the-air, or via cable, satellite, network, internetwork (includingthe Internet), displayed, distributed on storage media, or by any othermeans or technique that is humanly perceptible, without regard to theform or content of such data, and including but not limited to audio,video, audio/video, text, images, animations, databases, broadcasts,displays (including but not limited to video displays), web pages andstreaming media. As media is received on processing device 101,analytics software residing on processing device 101 collectsinformation relating to media data received from content source 125, andadditionally may collect data relating to network 110.

Data relating to the media data may include a “cookie”, also known as anHTTP cookie, which can provide state information (memory of previousevents) from a user's browser and return the state information to acollecting site, which may be the content source 125 or collection site121 (or both). The state information can be used for identification of auser session, authentication, user's preferences, shopping cartcontents, or anything else that can be accomplished through storing textdata on the user's computer. When setting a cookie, transfer of contentsuch as Web pages follows the HyperText Transfer Protocol (HTTP).Regardless of cookies, browsers request a page from web servers bysending a HTTP request. The server replies by sending the requested pagepreceded by a similar packet of text, called “HTTP response”. Thispacket may contain lines requesting the browser to store cookies. Theserver sends lines of Set-Cookie only if the server wishes the browserto store cookies. Set-Cookie is a directive for the browser to store thecookie and send it back in future requests to the server (subject toexpiration time or other cookie attributes), if the browser supportscookies and cookies are enabled. The value of a cookie can be modifiedby sending a new Set-Cookie: name=newvalue line in response of a pagerequest. The browser then replaces the old value with the new one.Cookies can also be set by JavaScript or similar scripts running withinthe browser. In JavaScript, the object document.cookie is used for thispurpose.

Various cookie attributes can be used: a cookie domain, a path,expiration time or maximum age, “secure” flag and “HTTPOnly” flag.Cookie attributes may be used by browsers to determine when to delete acookie, block a cookie or whether to send a cookie (name-value pair) tothe collection site 121 or content site 125. With regard to specific“cookies”, a session cookie may be used, which typically only lasts forthe duration of users using the website. A web browser normally deletessession cookies when it quits. A session cookie is created when noexpires directive is provided when the cookie is created. In anotherembodiment, a persistent cookie (or “tracking cookie”, “in-memorycookie”) may be used, which may outlast user sessions. If a persistentcookie has its Max-Age set to 1 year, then, within the year, the initialvalue set in that cookie would be sent back to a server every time auser visited that server. This could be used to record information suchas how the user initially came to the website. Also, a secure cookie maybe used when a browser is visiting a server via HTTPS, ensuring that thecookie is always encrypted when transmitting from client to server. AnHTTPOnly may also be used. On a supported browser, an HTTPOnly sessioncookie may be used for communicating HTTP (or HTTPS) requests, thusrestricting access from other, non-HTTP APIs (such as JavaScript). Thisfeature may be advantageously applied to session-management cookies.

Referring back to the example of FIG. 1, media data is received onprocessing device 101. At the time the media data is received, portablecomputing devices 102-104 are in the vicinity, and are configured toestablish Bluetooth communication (“pair”) with processing device 101.After Bluetooth communications are established, processing device 101collects the Bluetooth signal characteristics from each portablecomputing device. Under a preferred embodiment, Bluetooth signalcharacteristics relate to status parameters of a Bluetooth connectiontogether with any other signal strength values made available inBluetooth Core Specification. The Host Controller Interface (HCI)(discussed in greater detail below) provides access to three suchconnection status parameters, including Link Quality (LQ), ReceivedSignal Strength Indicator (RSSI), and Transmit Power Level (TPL). Allthese status parameters require the establishment of an active Bluetoothconnection in order to be measured. Another signal parameter, referredto as “Inquiry Result with RSSI”, alternately also be used, where theparameter perceives RSSI from the responses sent by its nearby devices.

Briefly, Link Quality (LQ) is an 8-bit unsigned integer that evaluatesthe perceived link quality at the receiver. It ranges from 0 to 255,where the larger the value, the better the link's state. For mostBluetooth modules, it is derived from the average bit error rate (BER)seen at the receiver, and is constantly updated as packets are received.Received Signal Strength Indicator (RSSI) is an 8-bit signed integerthat denotes received (RX) power levels and may further denote if thelevel is within or above/below the Golden Receiver Power Range (GRPR),which is regarded as the ideal RX power range. As a simplified example,when multipath propagation is present, RSSI is generally based on aline-of-sight (LOS) field strength and a reflected signal strength,where the overall strength is proportional to the magnitude of theelectromagnetic wave's E•field. Thus, when there is minimal reflectiveinterference, RSSI may be determined by 20 log (LOS+RS), where LOS isthe line-of-sight signal strength and RS is the reflected signal. Whenreflective interference is introduced RSSI becomes 20 log (LOS−RS).

Transmit Power Level (TPL) is an 8-bit signed integer which specifiesthe Bluetooth module's transmit power level (in dBm). Although there areinstances when a transmitter will use its device-specific default powersetting to instigate or answer inquiries, its TPL may vary during aconnection due to possible power control. “Inquiry Result with RSSI”works in a similar manner as a typical inquiry. In addition to the otherparameters (e.g., Bluetooth device address, clock offset) generallyretrieved by a normal inquiry, it also provides the RSSI value. Since itrequires no active connection, the radio layer simply monitors the RXpower level of the current inquiry response from a nearby device, andinfers the corresponding RSSI.

For system 100, transmission may occur from direct voltage controlledoscillator (VCO) modulation to IQ mixing at the final radio frequency(RF). In the receiver, a conventional frequency discriminator or IQdown-conversion combined with analog-to-digital conversion is used. TheBluetooth configuration for each of the portable computing devices102-104 and processing device 101 include a radio unit, a baseband linkcontrol unit, and link management software. Higher-level softwareutilities focusing on interoperability features and functionality areincluded as well. Enhanced Data Rate (EDR) functionalities may also beused to incorporate phase shift keying (PSK) modulation scheme toachieve a data rate of 2 or 3 Mb/s. It allows greater possibilities forusing multiple devices on the same connection because of the increasedbandwidth. Due to EDR having a reduced duty cycle, there is lower powerconsumption compared to a standard Bluetooth link.

As mentioned above, processing device 101 collects the Bluetooth signalcharacteristics from each portable computing device (102-104). At thesame time, processing device 101 is equipped with software allowing itto measure media data exposure for a given period of time (e.g., a webbrowsing session) to produce research data. The term “research data” asused herein means data comprising (1) data concerning usage of mediadata, (2) data concerning exposure to media data, and/or (3) marketresearch data. Under a preferred embodiment, when processing device 101detects media data activity, it triggers a timer task to run for apredetermined period of time (e.g., X minutes) until the activity isover. At this time, discovery of paired devices is performed to locateeach of the paired devices. Preferably, the UIDs of each device is knownin advance. For each device discovered and paired, processing device 101records each Bluetooth signal characteristic for the connection untilthe end of the session. Afterwards, the signal characteristics collectedfor each device, and the resultant research data for the session isforwarded to collection server 121 for further processing and/oranalysis. Collection server 121 may further be communicatively coupledto server 120 which may be configured to provide further processingand/or analysis, generate reports, provide content back to processingdevice 101, and other functions. Of course, these functions can readilybe incorporated into collection server 121, depending on the needs andrequirements of the designer.

Continuing with the example of FIG. 1, portable computing devices 102and 103 are illustrated as being paired and connected to processingdevice 101 during a media session. Being connected, the Bluetooth signalcharacteristics of portable computing devices 102 and 103 are collected(LQ, RSSI, TPL). Device 103 has previously been paired with processingdevice 101, but is outside the communication range of processing device101, and therefore is unable to connect. Depending on the characteristicused, the portable computing device (102, 102) with the bestcharacteristic is registered as being in closest proximity to processingdevice 101, and the portable device's user credited as being exposed tothe media data.

Accordingly, if RSSI signal strength is used, the average RSSI valueswould be collected for each device or distinct MAC, and proximity wouldbe detected. The strongest average RSSI value throughout the sessionwould determine the device having closest proximity (device 102). Underanother embodiment, the collected averaged RSSI values may be comparedwith averages from learned values to determine the nearest device. Anaverage distance could be calculated using the distance between eachdevice RSSI value and the learned values for each device. In thisexample, multiple samples would be taken (x1, x2, x3, x4, x5), wherelearned values contain multiple tuples for each device; each tuple wouldcontain a corresponding number of learned RSSI values (x1′, x2′, x3′,x4′ x5′). For each tuple, the average distance would be calculatedaccording to

$\sqrt{\left( {{x\; 1^{\prime}} - {x\; 1}} \right)^{2} + \left( {{x\; 2^{\prime}} - {x\; 2}} \right)^{2} + \left( {{x\; 3^{\prime}} - {x\; 3}} \right)^{2} + \left( {{x\; 4^{\prime}} - {x\; 4}} \right)^{2} + \left( {{x\; 5^{\prime}} - {x\; 5}} \right)^{2}}$Under another embodiment, multiple Bluetooth signal characteristics(e.g., LQ and RSSI) may be processed for determining proximity.

FIG. 2 shows an exemplary Bluetooth protocol stack utilized forcommunication in the embodiment of FIG. 1. Generally, the transitionfrom implementation in hardware and firmware (lower layers) to software(higher layers). If each of these groups of layers are separateentities, such as a PC card and laptop computer, then they cancommunicate with each other through Host Controller Interface 213 (HCI),which provides paths for data, audio, and control signals between theBluetooth module and host.

Radio 210 completes the physical layer by providing a transmitter andreceiver for two-way communication. Data packets are assembled and fedto the radio 210 by the baseband/link controller 211. The linkcontroller of 211 provides more complex state operations, such as thestandby, connect, and low-power modes. The baseband and link controllerfunctions are combined into one layer to be consistent with theirtreatment in the Bluetooth Specification. Link manager 212 provides linkcontrol and configuration through a low-level language called the linkmanager protocol (LMP).

Logical link control and adaptation protocol (L2CAP) 214 establishesvirtual channels between hosts that can keep track of severalsimultaneous sessions such as multiple file transfers. L2CAP 214 alsotakes application data and breaks it into Bluetooth-size portions fortransmission, and reverses the process for received data. RadioFrequency Communication (RFCOMM) 215 is a Bluetooth serial portemulator, and its main purpose is to “trick” application 220 intothinking that a wired serial port exists instead of an RF link. Finally,various software programs that are needed for different Bluetooth usagemodels enable resident application 220 to use Bluetooth. These includeservice discovery protocol (SDP) 219, object exchange (OBEX), 216telephony control protocol specification (TCS) 218, and WirelessApplication Protocol (WAP) 217. Bluetooth radio 210 and baseband I linkcontroller 211 consist of hardware that is typically available as one ortwo integrated circuits. Firmware-based link manager 212 and one end ofthe host controller interface 213, perhaps with a bus driver forconnection to the host, complete the Bluetooth module shown in FIG. 2.The remaining parts of tile protocol stack and the host end of HCI 213can be implemented in software on the host itself.

FIG. 3 illustrates an exemplary Bluetooth discovery process utilizing“Device A” 310 and “Device B” 311 using each respective baseband layer(320, 321). Here, Device A 310 is initiating service discover whileDevice B 311 establishes communications in order to make itdiscoverable. The process may be assisted using a service discoveryapplication from an access profile stored in each device.

The initial linking process 312 begins with an inquiry and page amongdevices in order to establish a piconet. In FIG. 3, Device A 310 isconfigured as a prospective slave (p-slave) and Device B 311 is aprospective master (p-master). As a p-master, Device B 311 must send itsfrequency hop synchronization (FHS) packet to a Device A 310 so thelatter can use the same hop sequence and phase used by the master.Preferably, a predetermined hop sequence or set of sequences, are usedfor paging and inquiries. For inquiries, the p-master may not know aboutnearby devices, so a single common hop sequence (one sequence forsending an inquiry and another for responding to the inquiry) is used byall devices for initial device discovery. A p-slave responding to aninquiry sends its FHS packet, within which is its Bluetooth deviceaddress (BD_ADDR). Now the p-master can create a new hopping sequencebased the BD_ADDR for transmitting a subsequent page for establishing apiconet with that p-slave.

Inquiries that are sent and replied by a device are typicallytransmitted at a device-specific default power setting. As a result,signal characteristics, such RSSI collected through an inquiry isrelatively free from the side-effect of power control. Accordingly, ainquiry fetched RSSI may provide finer measurements than theconnection-based RSSI.

For establishing channel 313, a hop channel set and the sequence of hopsthrough the channel set may be determined by the lower 28 bits of adevice's BD_ADDR, and the hop phase may be determined by the 27 mostsignificant bits of CLK. These two values are sent to a hop generator,and the output of this generator goes to the Bluetooth radio's frequencysynthesizer. In order to establish communications, Devices A and Bshould use the same hop channels, the same hop sequence from channel tochannel, and the same phase so that they hop together. Also, one deviceshould transmit while the other receives on the same frequency and viceversa. Multiple hop sequences and periods are configured to coverinquiry, page, and connect activity. These include channel hop sequence(used for normal piconet communications between master and slave(s)),page hop sequence (used by a p-master to send a page to a specificp-slave and to respond to the slave's reply), page response sequence(used by a p-slave to respond to a p-master's page), inquiry hopsequence (used by a p-master to send an inquiry to find Bluetoothdevices in range), and inquiry response sequence (used by a p-slave torespond to a p-master's inquiry).

Service discovery 314 is used for retrieving information required to setup a transport service or usage scenario, and may also be used to accessa device and retrieve its capabilities or to access a specificapplication and find devices that support that application. Retrievingcapabilities requires paging a device and forming an AsynchronousConnectionless Link (ACL) to retrieve the desired information, accessingapplications involves connecting to and retrieving information fromseveral devices that are discovered via an inquiry. Thus, servicediscovery may be used for browsing for services on a particular device,searching for and discovering services based upon desired attributes,and/or incrementally searching a device's service list to limit theamount of data to be exchanged. An L2CAP channel with a protocol servicemultiplexer (PSM) is used for the exchange of service-relatedinformation. Service discovery can have both client and serverimplementations, with at most one service discovery server on any onedevice. However, if a device is client only, then it need not have aservice discovery server. Each service is preferably listed in thedevice's SOP database as a service record having a uniqueServiceRecordHandle, and each attribute of the service record is givenan attribute ID and an attribute value. Attributes include the variousclasses, descriptors, and names associated with the service record.After service discovery is completed, the channel is released 315.

FIG. 4 illustrates an exemplary authentication configuration 400, whereBluetooth Pairing Service 415 sends API calls to Bluetooth Stack 410 andreceives back pairing events. Bluetooth Stack 410 transmits API calls toBluetooth helper service/function 411, which receives discovery enablesignals (inquiry, page scan) from Bluetooth Pairing Service 415.Bluetooth pairing information for Pairing Service 415 is communicatedfrom persistence/settings manager 413 and paired device list 412, whichpreferably retries information from system registry 414. BluetoothPairing Service 415 forwards information to device application 417, andmay further retrieve and communicate profile services 416 to application417 as well.

The authentication process verifies the identity of the device at theother end of a link. The verifier queries the claimant and checks itsresponse; if correct, then authentication is successful. Authorizationcan be used to grant access to all services, a subset of services, or tosome services when authentication is successful, but requires additionalauthentication based on some user input at the client device for furtherservices. The last item is usually implemented at the application layer.For Bluetooth Pairing Services 415, two devices become paired when theystart with the same PIN and generate the same link key, and then usethis key for authenticating at least a current communication session.The session can exist for the life of a L2CAP link (for Mode 2 security)or the life of the ACL link (for Mode 3 security). Pairing can occurthrough an automatic authentication process if both devices already havethe same stored PIN from which they can derive the same link keys forauthentication. Alternatively, either or both applications can ask theirrespective users for manual PIN entry. Once devices are paired they caneither store their link keys for use in subsequent authentications ordiscard them and repeat the pairing process each time they connect. Ifthe link keys are stored, then the devices are “bonded,” enabling futureauthentications to occur using the same link keys and without requiringthe user to input the PIN again. The concept of “trust” applies to adevice's authorization to access certain services on another device. Atrusted device is previously authenticated and, based upon thatauthentication, has authorization to access various services. Anuntrusted device may be authenticated, but further action is needed,such as user intervention with a password, before authorization isgranted to access services. Also, encryption may be used to furtherenhance security of connections.

FIG. 5 discloses one exemplary process for linking exposure to mediadata utilizing Bluetooth signal characteristics described above. In thebeginning, a web session 520 starts, which triggers Bluetooth pairing ofnearby devices 510. Once paired, the Bluetooth signal characteristics511 (“BSig”) are initially received. In the event that devices arealready paired and/or bonded, the process starts by acquiring Bluetoothsignal characteristics 511. Afterwards, a discovery process is run 512for retrieving information for transport service or usage scenario, andmay also be used to access a device and retrieve its capabilities or toaccess a specific application and find devices that support thatapplication. Under one embodiment, a timer is used for media dataexposure, wherein the timer can be set for specific time periods, or mayalternately be set and used to correspond with web sessions or otherevents. When the timer 513 runs out, the process ends in 517. Otherwise,the process moves to 514, where the pairing is validated to ensure thata Bluetooth device is not moving out of range or otherwise compromisingthe connection. If the pairing validation produces a negative result,the process continues to look for the device via 512 for the time period513. If the pairing validation is affirmative, the Bluetooth signalcharacteristics are logged 515 and stored 516 for the duration of themeasurement (513). It should be understood that BSig block 515 mayinclude Received Signal Strength Indicator (RSSI) value, a TransmitPower Level (TPL) value and/or a Link Quality (LQ) value.

It is understood that the examples above are provided as examples, andare not intended to be limiting in any way. Under an alternateembodiment, Bluetooth signal strengths may be approximated to determinedistance. As explained above, an RSSI value provides the distancebetween the received signal strength and an optimal receiver power rankreferred to as the “golden receiver power rank.” The golden receiverpower rank is limited by two thresholds. The lower threshold may bedefined by an offset of 6 dB to the actual sensitivity of the receiver.The maximum of this value is predefined by −56 dBm. The upper thresholdmay be 20 dB over the lower one, where the accuracy of the upperthreshold is about ±6 dB. Where S is assigned as the received signalstrength, the value of S is determined by: (1) S=RSSI+T_(U), for RSSI>0and (2) S=RSSI−T_(L), for RSSI<0, where T_(U)=T_(L)+20 DdB. Here, T_(U)refers to the upper threshold, and T_(L) refers to the lower threshold.The definition of the Bluetooth golden receiver limits the measurementof the RSSI to a distance. In order to measure the most uniquecharacteristics of the signal, only measurements that result in apositive range of the RSSI should be considered for a functionalapproximation. The approximation may be calculated by choosing the bestfitted function given by determining and minimizing the parameters of aleast square sum of the signal strength measurements.

With regard to media data exposure measurement, the preferred embodimentcollects research data on a computer processing device, associates itwith the collected Bluetooth signal characteristics, and (a) transmitsthe research data and Bluetooth signal characteristics to a remoteserver(s) (e.g., collection server 121) for processing, (b) performsprocessing of the research data and Bluetooth signal characteristics inthe computer processing device itself and communicates the results tothe remote server(s), or (c) distributes association/processing of theresearch data and Bluetooth signal characteristics between the computerprocessing device and the remote server(s).

Under another embodiment, one or more remote servers are responsible forcollecting research data on media data exposure. When Bluetooth signalcharacteristics are received from a computer processing device, thesignal characteristics are associated with the research data (e.g.,using time stamps) and processed. This embodiment is particularlyadvantageous when remote media data exposure techniques are used toproduce research data. One technique, referred to as “logfile analysis,”reads the logfiles in which a web server records all its transactions. Asecond technique, referred to as “page tagging,” uses JavaScript on eachpage to notify a third-party server when a page is rendered by a webbrowser. Both collect data that can be processed to produce web trafficreports together with the Bluetooth signal characteristics. In certaincases, collecting web site data using a third-party data collectionserver (or even an in-house data collection server) requires anadditional DNS look-up by the user's computer to determine the IPaddress of the collection server. As an alternative to logfile analysisand page tagging, “call backs” to the server from the rendered page maybe used to produce research data. In this case, when the page isrendered on the web browser, a piece of Ajax code calls to the server(XMLHttpRequest) and passes information about the client that can thenbe aggregated.

Turning to FIG. 6, an exemplary portion of a report utilizing Bluetoothsignal characteristics is illustrated, where five different kinds ofmedia data (Media1-Media5) were received on a computer processing device(COMP1). At that time, four portable computing devices (Device 1-Device4) were either (a) previously paired with the computing device, oractively paired with the computing device during the media session inwhich the five media data were received. The body of the table in FIG. 6is populated with the collected signal strengths (e.g., average RSSI)for each device. It this example, Device 1 had either a minimalconnection (020) or no connection at all (000) throughout the session,and was therefore not credited with being exposed to any of the mediadata. Device 2 was measured as having the strongest signal strength forMedia1 and Media 5 (0127 and 124, respectively), and was thereforecredited with being exposed to the media data. While Device 2 wasmeasured as being in proximity to computer processing device for Media2and Media3, Device 3 was measured as having the strongest signalstrength (100 and 110), and thus Device 3 received credit with beingexposed to media data. Similarly, Device 4 was measured as having thestrongest signal strength at the time Media4 was received, and thusreceives the media exposure credit. Under one embodiment, thresholdmedia strength can be implemented to reduce the possibility of “falsepositives” in crediting media exposure. In this example, if threedevices are detected in a vicinity of a portable computing device, butthe signal strengths are not sufficiently high enough, none of thedevices are credited with being exposed to the media data.

While at least one example embodiment has been presented in theforegoing detailed description, it should be appreciated that a vastnumber of variations exist. It should also be appreciated that theexample embodiment or embodiments described herein are not intended tolimit the scope, applicability, or configuration of the invention in anyway. Rather, the foregoing detailed description will provide thoseskilled in the art with a convenient and edifying road map forimplementing the described embodiment or embodiments. It should beunderstood that various changes can be made in the function andarrangement of elements without departing from the scope of theinvention and the legal equivalents thereof.

What is claimed is:
 1. A method to collect media exposure data,comprising: collecting a cookie at a client device based on mediaaccessed via a web page at the client device; selecting a portabledevice identifier at the client device, the portable device identifiercorresponding to a closest one of a plurality of portable devices inwireless communication with the client device, the portable deviceidentifier associated with a particular person; and in response toinstructions embedded in the media, sending a hypertext transferprotocol (HTTP) request to a server, the HTTP request including thecookie, the portable device identifier, and information identifyingexposure to the media.
 2. A method as defined in claim 1, furthercomprising identifying the closest one of the portable devices by:collecting signal characteristics corresponding to the wirelesscommunication between the portable devices and the client device; andselecting the closest one of the portable devices based on one of thesignal characteristics being comparatively best relative to the othersignal characteristics.
 3. A method as defined in claim 2, wherein thesignal characteristic is one of a link quality, a signal strength, or atransmit power level.
 4. A method as defined in claim 1, wherein thewireless communication is a Bluetooth communication.
 5. A method asdefined in claim 1, wherein the cookie, the portable device identifier,and the information identifying exposure to the media cause the serverto credit the particular person with being exposed to the media.
 6. Amethod as defined in claim 1, wherein the media is at least one ofaudio, video, text, an image, an animation, a database, a web page,broadcast media, or streaming media.
 7. A method as defined in claim 1,further comprising, in response to detecting that the media is accessedat the client device: establishing the wireless communications betweenthe client device and the plurality of portable devices; and obtainingsignal characteristics corresponding to the wireless communications ofthe portable devices, the signal characteristics to facilitate theselecting of the portable device identifier at the client device.
 8. Anapparatus to collect media exposure data, comprising: a processor; and astorage memory comprising computer readable instructions that, whenexecuted, cause the processor to: collect a cookie at a client devicebased on media accessed via a web page at the client device; select aportable device identifier at the client device, the portable deviceidentifier corresponding to a closest one of a plurality of portabledevices in wireless communication with the client device, the portabledevice identifier associated with a particular person; and in responseto instructions embedded in the media, send a hypertext transferprotocol (HTTP) request to a server, the HTTP request including thecookie, the portable device identifier, and information identifyingexposure to the media.
 9. An apparatus as defined in claim 8, whereinthe computer readable instructions, when executed, further cause theprocessor to: collect signal characteristics corresponding to thewireless communication between the portable devices and the clientdevice; and select the closest one of the portable devices based on oneof the signal characteristics being comparatively best relative to theother signal characteristics.
 10. An apparatus as defined in claim 9,wherein the signal characteristic is one of a link quality, a signalstrength, or a transmit power level.
 11. An apparatus as defined inclaim 8, wherein the wireless communication is a Bluetoothcommunication.
 12. An apparatus as defined in claim 8, wherein thecookie, the portable device identifier, and the information identifyingexposure to the media cause the server to credit the particular personwith being exposed to the media.
 13. An apparatus as defined in claim 8,wherein the media is at least one of audio, video, text, an image, ananimation, a database, a web page, broadcast media, or streaming media.14. An apparatus as defined in claim 8, wherein the computer readableinstructions, when executed, further cause the processor to: establishthe wireless communications between the client device and the pluralityof portable devices; and obtain signal characteristics corresponding tothe wireless communications of the portable devices, the signalcharacteristics to facilitate the selecting of the portable deviceidentifier at the client device.
 15. A computer readable storage deviceor storage disk comprising computer readable instructions that, whenexecuted, cause a processor to at least: collect a cookie at a clientdevice based on media accessed via a web page at the client device;select a portable device identifier at the client device, the portabledevice identifier corresponding to a closest one of a plurality ofportable devices in wireless communication with the client device, theportable device identifier associated with a particular person; and inresponse to instructions embedded in the media, send a hypertexttransfer protocol (HTTP) request to a server, the HTTP request includingthe cookie, the portable device identifier, and information identifyingexposure to the media.
 16. A computer readable storage device or storagedisk as defined in claim 15, wherein the computer readable instructions,when executed, cause the processor to: collect signal characteristicscorresponding to the wireless communication between the portable devicesand the client device; and select the closest one of the portabledevices based on one of the signal characteristics being comparativelybest relative to the other signal characteristics.
 17. A computerreadable storage device or storage disk as defined in claim 16, whereinthe signal characteristic is one of a link quality, a signal strength,or a transmit power level.
 18. A computer readable storage device orstorage disk as defined in claim 15, wherein the wireless communicationis a Bluetooth communication.
 19. A computer readable storage device orstorage disk as defined in claim 15, wherein the cookie, the portabledevice identifier, and the information identifying exposure to the mediacause the server to credit the particular person with being exposed tothe media.
 20. A computer readable storage device or storage disk asdefined in claim 15, wherein the media is at least one of audio, video,text, an image, an animation, a database, a web page, broadcast media,or streaming media.
 21. A computer readable storage device or storagedisk as defined in claim 15, wherein the computer readable instructions,when executed, cause the processor to: establish the wirelesscommunications between the client device and the plurality of portabledevices; and obtain signal characteristics corresponding to the wirelesscommunications of the portable devices, the signal characteristics tofacilitate the selecting of the portable device identifier at the clientdevice.